This invention relates to the discovery and asexual propagation of a new and distinct variety of Pistachio tree, Pistachio atlantica×P. integerrima cv. ‘Wonderful Pistachio Rootstock #1’ as herein described and illustrated. The new variety is a hybrid of P. atlantica and P. integerrima which was first discovered on cultivated land from trees grown from seed produced by a cross of the two parent species. The new variety was discovered and further characterized, and propagated by Joe Macllvaine, Eric Mercure and John Etchamendy in the San Joaquin Valley, Kern County, Calif. The initial discovery, characterization and propagation of the new variety took place from 2006 to 2010.
The new variety ‘Wonderful Pistachio Rootstock #1’ is characterized by producing large leaves, reddish-green new foliage, dark green mature foliage and upright habits with rounded crown. The new variety is useful as a rootstock to nut bearing pistachio.
The new variety ‘Wonderful Pistachio Rootstock #1’ was first asexually propagated in 2007 by Eric Mercure by meristem or shoot tip tissue culture at Southern San Joaquin Valley in Kern County, Calif. and established and transmitted through succeeding propagation by air-layering.
The male parent is P. integerrima and the female parent is P. atlantica. The date of first sowing was 1990, and the date of first flowering was 1996.
The new variety ‘Wonderful Pistachio Rootstock #1’ differs from its male parent P. integerrima in that the leaves and leaflets are shorter. Also, the leaflet base is more rounded in the new variety. In addition, the leaves are less red when emerging and fall off sooner.
The new variety ‘Wonderful Pistachio Rootstock #1’ differs from its female parent P. atlantica in that new variety is more vigorous and is believed to be more resistant to verticillium disease. The leaflets of the new variety are larger and less rounded with a faster growth rate. The new variety has an overall larger size canopy.
The new variety can be distinguished from other available varieties by its yield characteristics. The closest available varieties are ‘Pioneer Gold’ and ‘UCB1’, an P. atlantica×P. integerrima hybrid. Yields on P. vera have been observed to be consistently higher on mature trees on the new rootstock variety when compare to Pioneer Gold and UCB1. The new variety ‘Wonderful Pistachio Rootstock #1’ can also be distinguished from ‘Pioneer Gold’ by the leaf shape.
The new ‘Wonderful Pistachio Rootstock #1’ has been shown to maintain its distinguishing characteristics through successive asexual propagations by, for example, meristem or shoot tip tissue culture and air layering.
Variations of the usual magnitude from the characteristics described herein may occur with changes in growing conditions, irrigation, fertilization, pruning, management and with climatic variation.
The new variety ‘Wonderful Pistachio Rootstock #1’ was analyzed to identify unique molecular markers. In one set of experiments primers were used to amplify a variety of simple sequence repeats (SSRs), essentially as described in Vendramin et al. Mol. Ecology Res. (2010) 10(3):576-579. SSRs were identified from a GT-enriched library prepared from P. atlantica and P. integerrima DNA and from the literature (Vendramin et al., Ahmad et al. J. Amer. Soc. Hort. Sci. (2003) 128(6):898-903 and Albaladejo et al. Mol. Ecology Res. (2008) 8:904-906). Primers were prepared and used to amplify relevant loci. ‘Wonderful Pistachio Rootstock #1’ was compared to its parents, P. atlantica and P. integerrima, as well as UCB1 and two additional unpatented varieties. ‘Wonderful Pistachio Rootstock #1’ was uniquely identified by products at about 625 and 655 bp using a primer set corresponding to EPV F013 from Vendramin et al.
DNA amplification fingerprinting (DAF) was also used to analyze ‘Wonderful Pistachio Rootstock #1’, essentially as described in Caetano-Anolles BioTechniques (1998) 25:472-480 and Trigiano, R. N. and G. Caetano-Anolles. HortTechnology (1998) 8(3):413-423. Two DAF primers, 8.6D and 8.6J (Trigiano, R. N. et al. HortTechnology (2004) 39(3):489-492) were able to distinguish ‘Wonderful Pistachio Rootstock #1’ from ‘UCB1’, ‘Wonderful Pistachio Rootstock #2’ (U.S. Plant Pat. application Ser. No. 13/998,774) and the two unpatented varieties, as well as from P. atlantica and P. integerrima. Primer 8.6D produced a doublet at about 410 bp that was only present in ‘Wonderful Pistachio Rootstock #1’ and ‘UCB1’. The doublet was not present in the parent varieties, ‘Wonderful Pistachio Rootstock #2’ or in the unpatented varieties. Primer 8.6J was then able to distinguish ‘Wonderful Pistachio Rootstock #1’ from ‘UCB1’, as it produced heavy bands at 150-200 bp in ‘Wonderful Pistachio Rootstock #1’. These bands were not present for ‘UCB1’ or for the unpatented varieties. In ‘Wonderful Pistachio Rootstock #2’ Primer 8.6J produced a single band at about 425 bp.